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Scorpius Clusters

July 24, 2016

Two big, beautiful stellar families narrowly avoid the sting of the scorpion. They stand just above the stars that mark the scorpion’s stinger.

The families are the star clusters M6 and M7.

M7 is the brighter of the two, mainly because it’s only about half as far as M6. Each cluster contains perhaps a few hundred stars, spread across a dozen or more light-years.

Each cluster forms a tight-knit family. In both cases, the stars were born from a single giant cloud of gas and dust. The shockwave from an exploding star or some other event caused the cloud to collapse and split into smaller clumps of material. These clumps then collapsed more, eventually forming stars.

Today, the stars of each cluster remain bound together by their mutual gravitational pull. That means they circle the center of the Milky Way together — a family of stars sharing a ride around the galaxy.

To find the clusters, first find Scorpius. The constellation is quite low in the south at nightfall. Its brightest stars form a pattern that really does resemble a scorpion, with the head at the top and the tail to the lower left.

If you line up the two stars at the tip of the tail — the “stinger” — and extend that line to the upper left, you’ll come to M7. Under dark skies, it’s visible to the unaided eye as a hazy smudge of light. Slightly fainter M6 is to the upper right. Binoculars reveal many of the individual members of these beautiful stellar families.

Script by Damond Benningfield

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